1. Field of the Invention
The present invention relates generally to mobile stations and base station transceiver systems, and more particularly to the selection of base station transceiver systems based on service communication type (e.g. 2G or 3 G communication service).
2. Description of the Related Art
A wireless communication device, such as a cellular telephone or mobile station, is often capable of making and receiving voice calls and/or sending and receiving data over a wireless communication network. Before it is able to do this, the cellular mobile station selects, acquires, and registers with one of a plurality of communication networks which are available within a given geographic coverage area. After registering with the selected network, the mobile station operates in an idle mode where it “camps-on” a particular wireless communication channel of the network to monitor for its calls or messages. The mobile station also monitors for the availability of other preferred systems and performs “handoffs” to these systems if necessary. “Network selection” is the process performed by the mobile station for selecting the communication network with which to communicate.
Base station transceiver systems may be coupled to different networks which may provide different services for a mobile station. Third Generation (3G) wireless networks provide for high speed packet data services, a big improvement over earlier developed circuit-switched wireless networks. As is well documented, 3G services are typically associated with Universal Mobile Telecommunications System (UMTS), Enhanced Data for Global Evolution (EDGE), Wideband Code Division Multiple Access (WCDMA), and CDMA2000 (1XRTT, 1XEV-DO, and 1XEV-DV) technologies. On the other hand, Second Generation (2G) communication service is a circuit-switched based system and is associated with basic CDMA (e.g. CDMAone), Time Division Multiple Access (TDMA), and GSM technologies. 2G typically provides a service that is less than 65 kilobits per second (kbps). 2.5 Generation (2.5G) service was established as a bridge to transition from 2G to 3G and is typically associated with CDMA2000 (1X) and General Packet Radio Service (GPRS) technologies. All of the above technologies proceed the primarily “analog” or First Generation (1G) service, which is generally associated with Advanced Mobile Phone Service (AMPS).
Using conventional techniques, a mobile station performs network selection based on information on a Subscriber Identity Module (SIM) card, a Removable User Identity Module (R-UIM), or a Preferred Roaming List (PRL) that resides in non-volatile memory. This information is typically programmed by a service provider and provides the mobile station with various system selection criteria, such as which systems the mobile station should attempt to acquire first, which systems are preferred over others, which systems are roaming systems, etc. The selection criteria are usually quite restrictive and do not take into account the primary service that a particular mobile station is expected to provide.
In contrast to standard cellular telephones, other types of portable devices such as personal digital assistants (PDAs), laptop computers, and portable e-mail devices, are better known to provide for the organization and management of text, files, messages, and/or other data. However, wireless data communication services, such as wireless e-mail and Internet access services, are becoming more and more popular in connection with such devices. Mobile stations providing for combined capabilities (e.g. both voice and advanced data communication) also exist and are becoming increasingly popular.
In order to operate fully as intended, these mobile stations must have the appropriate communication services supported and made available by the communication network that it is registered with. Ideally, a communication system should support and make available all the different types of communication services that a mobile station is capable of providing for the ultimate benefit of the end user. In practice, however, a given communication network can only provide services that are defined with the standard that it conforms to. For example, a 2 G communication network cannot provide all services defined in 3G. However, there may be other communication networks in the same geographical area which conform to a more advanced standard and provide services that are more suitable for the mobile station.
As apparent, conventional network selection does not take into consideration the availability of different service offerings in the decision-making process. As a result, an inadequate communication network may be selected by the mobile station. For example, a mobile station may select a communication network that provides an acceptable voice service (a circuit-switched data service) but not a high speed packet data service despite the availability of another adequate network capable of providing both the voice and the high speed packet data service in the same geographical region. Such conventional operation is undesirable, especially for application-specific mobile stations (e.g. portable wireless e-mail devices).
As a particular illustrative example, one conventional network selection criteria defined by CDMA service providers involves a preference to select and communicate with a base station transceiver system of a Personal Communication Service (PCS) band (i.e. a 1900 MHz band) over that of a standard cellular network band (i.e. a 800 MHz band). However, the preferred PCS band may or may not offer a 3G service. In fact, the PCS network may provide a 2G service and the standard cellular band may offer a 3G service. In such a case, a conventional mobile station will not provide the data service (e.g. a high speed packet data service) to the end user even though it is available in the region. Furthermore, there could be other beneficial features in a 3G network, such as a “quick paging channel” in a 1XRTT network. Usage of the quick paging channel can significantly increase the standby battery life of the mobile station. In certain 2G/3G boundaries, however, if the mobile station is using conventional network selection methods that do not take into account the protocol revision of the transceiver system, the mobile station may end up in a “more preferred” 2G network and lose the benefit of the quick paging channel. The reverse may also be true in terms of band preference, since it depends on the band available to the service provider.
Accordingly, there is a resulting need for mobile station methods and apparatus for selecting a communication network that overcome the deficiencies of the prior art.